Resource assignment in NR-SS

ABSTRACT

Certain aspects of the present disclosure relate to a method and apparatus for receiving a medium occupation and a resource block group (RBG) size from a gNB, wherein the radio block group size is based on a bandwidth part (BWP) configuration. In one example, UEs with smaller BWP have finer granularity in RBG size in terms of PRBs, while UEs with larger BWP may have a coarser granularity in RBG size in terms of PRBs. An additional guard band may be used if the gNB reserves some channels such that not all of the BW is occupied. For example, if the gNB reserves the 20 MHz channel, it may perform better by adding additional guard band on each side of the 20 MHz bandwidth to accommodate an adjacent channel leakage-power ratio (ACLR). Another aspect of the present disclosure relates to assigning a UE an interlace with equally spaced PRBs.

This application is a continuation of U.S. patent application Ser. No.16/224,154, entitled “RESOURCE ASSIGNMENT IN NR-SS,” filed in the UnitedStates Patent and Trademark Office on Dec. 18, 2018, which claimspriority to and the benefit of U.S. Provisional Patent Application No.62/608,341, entitled “RESOURCE ASSIGNMENT IN NR-SS,” filed in the UnitedStates Patent and Trademark Office on Dec. 20, 2017, the entire contentsof which are incorporated herein by reference as is fully set forthbelow in their entirety and for all applicable purposes.

BACKGROUND Field of Disclosure

The following relates generally to unlicensed, wireless communication,and more specifically to uplink communications.

Description of Related Art

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, and orthogonal frequencydivision multiple access (OFDMA) systems. A wireless multiple-accesscommunications system may include a number of base stations, eachsimultaneously supporting communication for multiple communicationdevices, which may be otherwise known as user equipment (UE).

SUMMARY

A method, and apparatus for receiving resources at a user equipment (UE)is described. The method, and apparatus may include applying alisten-before-talk (LBT) procedure for sending a medium, and receivinginformation comprising a medium occupation and a resource block group(RBG) size from a gNB, wherein the resource block group size is based ona medium occupation.

In another example, the method and apparatus further comprises a nodewith smaller channel occupancy using a finer RBG granularity insignalling and a node with larger channel occupancy using a coarser RBGgranularity in signalling.

In another example, the method and apparatus further comprises receivingan additional guard band around an occupied medium, wherein the guardband is assigned around the occupied medium to avoid adjacent channelleakage-power if a node is not able to access the adjacent channels.

In another example, there is there is an implicit mapping between theRBG size and the medium occupancy.

In another example, the method and apparatus further involves reducingresource allocation (RA) overhead by receiving a starting PRB, RBG, orinterlace, receiving a number of the RBs, RBGs, or interlaces acrosschannels including those channels without medium access, andautomatically skipping PRBs, RBGs, or interlaces in the guard band andin unoccupied channels.

In still another example, the method and apparatus further involvesreducing resource allocation (RA) overhead by joint coding a resourceallocation (RA) indication and a medium occupation index comprising,indicating a starting PRB in a first allocated channel and an end PRB ina last allocated channel, and indicating medium occupancy on the firstand last allocated channel.

Also, another method, and apparatus is described which includesassigning a UE an interlace with equally spaced PRBs across a channel orassigning an interlace of equally spaced PRBs across a plurality ofchannels within a system bandwidth.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram conceptually illustrating an exampletelecommunications system, in accordance with certain aspects of thepresent disclosure.

FIG. 2 is a block diagram illustrating an example logical architectureof a distributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 3 is a diagram illustrating an example physical architecture of adistributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 4 is a block diagram conceptually illustrating a design of anexample base station (BS) and user equipment (UE), in accordance withcertain aspects of the present disclosure;

FIG. 5A is a diagram illustrating an example of a downlink (DL)-centricsubframe according to some aspects of the present disclosure;

FIG. 5B is a diagram illustrating an example of an uplink (UL)-centricsubframe according to some aspects of the present disclosure;

FIG. 6 discloses a message from the RRC called the RRC configurationmessage which carries a medium occupation indication and an RBallocation within the occupied channels;

FIG. 7 shows a medium occupation to RBG size mapping for one to fourchannels, where 20 MHz equals one channel, 40 MHz equals two channels,60 MHz equals three channels and 80 MHz equals four MHz;

FIG. 8 discloses using a bitmap to configure a UE with a channel and anRBG size;

FIG. 9A illustrates an allocation of PRBs and RBGs to channels 0 thru 3,where 50 PRBs per channel are allocated, along with an RBG size of 4PRBs;

FIG. 9B illustrates an allocation of PRBs and RBGs to channels 0 and 3;

FIG. 10A is a flowchart of the steps taken by a BS to indicate mediumoccupation along with RBG size to UE;

FIG. 10B is a flowchart of the steps taken by a UE when receiving emedium occupation along with RBG size from the BS;

FIG. 11A is a flowchart of the steps taken to reduce resource allocationoverhead by receiving a starting PRB, RBG, or interlace, spanning anumber of said RBs, RBGs, or interlaces across multiple channelsincluding those channels without medium access, and automaticallyskipping PRBs, RBGs, or interlaces in the guard band and in unoccupiedchannels;

FIG. 11B is a flowchart of the steps taken to reduce resource allocationoverhead by joint coding a resource allocation (RA) indication and amedium occupation index;

FIG. 12A shows multiple interlaces with multiple equally spaced PRBs,such as a first interlace of PRBs, interlace 0, and a second interlaceof PRBs, interlace 320;

FIG. 12B is an interlace within a 20 MHz channel which is composed often equally spaced physical resource blocks;

FIG. 12C is an interlace within a system bandwidth of 80 MHz comprisingfour 20 MHz channels where the PRBs are equally spaced 3 PRBs apart;

FIG. 13 illustrates certain components that may be included within abase station; and

FIG. 14 illustrates certain components that may be included within awireless communication device.

DETAILED DESCRIPTION

With 5G NR, subcarrier spacing may be scaled. Also, the waveformsselected for 5G include cyclic prefix-orthogonal frequency-divisionmultiplexing (CP-OFDM) and DFT-Spread (DFT-S) OFDM. In addition, 5Gallows for switching between both CP OFDM and DFT-S-OFDM on the uplinkto get the MIMO spatial multiplexing benefit of CP-OFDM and the linkbudget benefit of DFT-S OFDM. With LTE, orthogonal frequency-divisionmultiple access (OFDMA) communications signals may be used for downlinkcommunications, while Single-Carrier Frequency-Division Multiple Access(SC-FDMA) communications signals may be used for LTE uplinkcommunications. The DFT-s-OFDMA scheme spreads a plurality of datasymbols (i.e., a data symbol sequence) over a frequency domain which isdifferent from the OFDMA scheme. Also, in comparison to the OFDMAscheme, the DFT-s-OFDMA scheme can greatly reduce a PAPR of atransmission signal. The DFT-s-OFDMA scheme may also be referred to asan SC-FDMA scheme.

Scalable OFDM multi-tone numerology is another feature of 5G. Priorversions of LTE supported a mostly fixed OFDM numerology of 15 kHzspacing between OFDM tones (often called subcarriers) and carrierbandwidths up to 20 MHz. Scalable OFDM numerology has been introduced in5G to support diverse spectrum bands/types and deployment models. Forexample, 5G NR is able to operate in mmWave bands that have widerchannel widths (e.g., 100 s of MHz) than currently in use in LTE. Also,the OFDM subcarrier spacing is able to scale with the channel width, sothe FFT size scales such that processing complexity does not increaseunnecessarily for wider bandwidths. In the present application,numerology refers to the different values different features of acommunication system can take such as subcarrier spacing, cyclic prefix,symbol length, FFT size, TTI, etc.

Also in 5G NR, cellular technologies have been expanded into theunlicensed spectrum, both stand-alone and licensed-assisted (LAA). Inaddition, the unlicensed spectrum may occupy frequencies up to 60 GHzalso known as mmWave. The used of unlicensed bands provides addedcapacity.

A first member of this technology family is referred to as LTEUnlicensed or LTE-U. By aggregating LTE in unlicensed spectrum with an‘anchor’ channel in licensed spectrum, faster downloads are enabled forcustomers. Also, LTE-U shares the unlicensed spectrum fairly with Wi-Fi.This is an advantage because in the 5 GHz unlicensed band where Wi-Fidevices are in wide use, it is desirable for LTE-U to coexist with theWi-Fi. However, an LTE-U network may cause RF interference to anexisting co-channel Wi-Fi device. Choosing a preferred operating channeland minimizing the interference caused to nearby Wi-Fi networks is agoal for LTE-U devices. However, the LTE-U single carrier (SC) devicemay operate on the same channel as Wi-Fi if all available channels areoccupied by Wi-Fi devices. To coordinate spectrum access between LTE-Uand Wi-Fi, the energy across the intended transmission band is firstdetected. This energy detection (ED) mechanism informs the device ofongoing transmissions by other nodes. Based on this ED information, adevice decides if it should transmit. Wi-Fi devices do not back off toLTE-U unless its interference level is above an energy detectionthreshold (−62 dBm over 20 MHz). Thus, without proper coexistencemechanisms in place, LTE-U transmissions could cause considerableinterference on a Wi-Fi network relative to Wi-Fi transmissions.

Licensed Assisted Access or LAA is another member of the unlicensedtechnology family. Like LTE-U, it also uses an anchor channel inlicensed spectrum. However, it also adds “listen before talk” (LBT) tothe LTE functionality.

A gating interval may be used to gain access to a channel of a sharedspectrum. The gating interval may determine the application of acontention-based protocol such as an LBT protocol. The gating intervalmay indicate when a Clear Channel Assessment (CCA) is performed. Whethera channel of the shared unlicensed spectrum is available or in use isdetermined by the CCA. If the channel is “clear” for use, i.e.,available, the gating interval may allow the transmitting apparatus touse the channel. Access to the channel is typically for a predefinedtransmission interval and allows the channel to be used by a gNB and UEscommunicating with the gNB. Thus, with unlicensed spectrum, a “listenbefore talk” procedure is performed before transmitting a message. Ifthe channel is not cleared for use, then a device will not transmit.

Another member of this family of unlicensed technologies is LTE-WLANAggregation or LWA which utilizes both LTE and Wi-Fi. Accounting forboth channel conditions, LWA can split a single data flow into two dataflows which allows both the LTE and the Wi-Fi channel to be used for anapplication Instead of competing with Wi-Fi, the LTE signal is using theWLAN connections seamlessly to increase capacity.

The final member of this family of unlicensed technologies is MulteFire.MuLTEfire opens up new opportunities by operating 4G LTE technologysolely in unlicensed spectrum such as the global 5 GHz. Unlike LTE-U andLAA, MulteFire allows entities without any access to licensed spectrum.Thus, it operates in unlicensed spectrum on a standalone basis, that is,without any anchor channel in the licensed spectrum. Thus, MulteFirediffers from LTE-U, LAA and LWA because they aggregate unlicensedspectrum with an anchor in licensed spectrum. Without relying onlicensed spectrum as the anchoring service, MulteFire allows for Wi-Filike deployments. A MulteFire network may include access points (APs)and/or base stations 105 communicating in an unlicensed radio frequencyspectrum band, e.g., without an licensed anchor carrier.

The (DRS Measurement Timing Configuration) is a technique that allowsMulteFire to transmit but with minimal interference to other unlicensedtechnology including Wi-Fi. Additionally, the periodicity of discoverysignals is very sparse. This allows Multefire to access channelsoccasionally, transmit discovery and control signals, and then vacatethe channels. Since the unlicensed spectrum is shared with other radiosof similar or dissimilar wireless technologies, a so-calledlisten-before-talk (LBT) method is applied for channel sensing. LBTinvolves sensing the medium for a predefined minimum amount of time andbacking off if the channel is busy. Therefore, the initial random access(RA) procedure for standalone LTE-U should involve as few transmissionsas possible and also have low latency, such that the number of LBToperations can be minimized and the RA procedure can then be completedas quickly as possible.

Leveraging a DMTC (DRS Measurement Timing Configuration) window,MulteFire algorithms search and decode reference signals in unlicensedband from neighboring base stations in order to know which base stationwould be best for serving the user. As the caller moves past one basestation, their UE sends a measurement report to it, triggering ahandover at the right moment, and transferring the caller (and all oftheir content and information) to the next base station.

Since LTE traditionally operated in licensed spectrum and Wi-Fi operatedin unlicensed bands, coexistence with Wi-Fi or other unlicensedtechnology was not considered when LTE was designed. In moving to theunlicensed world, the LTE waveform was modified and algorithms wereadded in order to perform Listen Before Talk (LBT). This allows us torespect unlicensed incumbents including Wi-Fi by not just acquiring achannel and immediately transmitting. The present example supports LBTand the detection and transmission of WCUBS (Wi-Fi Channel Usage BeaconSignal) for ensuring coexistence with Wi-Fi neighbors.

MulteFire was designed to “hear” a neighboring Wi-Fi base station'stransmission (because it's all unlicensed spectrum). MulteFire listensfirst, and autonomously makes the decision to transfer when there is noother neighboring Wi-Fi transmitting on the same channel. This techniqueensures co-existence between MulteFire and Wi-Fi.

Additionally, we adhere to the unlicensed rules and regulations set by3GPP and the European Telecommunications Standards Institute (ETSI),which mandates the −72 dBm LBT detection threshold. This further helpsus de-conflict with Wi-Fi. MulteFire's LBT design is identical to thestandards defined in 3GPP for LAA/eLAA and complies with ETSI rules.

An expanded functionality for 5G involves the use of 5G NR SpectrumSharing, or NR-SS. 5G spectrum sharing enables enhancement, expansion,and upgrade of the spectrum sharing technologies introduced in LTE.These include LTE Wi-Fi Aggregation (LWA), License Assisted Access(LAA), enhanced License Assisted Access (eLAA), and CBRS/License SharedAccess (LSA).

Aspects of the disclosure are initially described in the context of awireless communication system. Aspects of the disclosure are thenillustrated by and described with reference to apparatus diagrams,system diagrams, and flowcharts that relate to receiving on transmit andtransmitting on receive.

FIG. 1 illustrates an example wireless network 100, such as a new radio(NR) or 5G network, in which aspects of the present disclosure may beperformed.

As illustrated in FIG. 1 , the wireless network 100 may include a numberof BSs 110 and other network entities. A BS 110 may be a station thatcommunicates with UEs 120. Each BS 110 may provide communicationcoverage for a particular geographic area. In 3GPP, the term “cell” canrefer to a coverage area of a Node B and/or a Node B subsystem servingthis coverage area, depending on the context in which the term is used.In NR systems, the term “cell” and eNB, Node B, 5G NB, AP, NR BS, NR BS,5G Radio NodeB (gNB), or TRP may be interchangeable. In some examples, acell may not necessarily be stationary, and the geographic area of thecell may move according to the location of a mobile base station 120. Insome examples, the base stations 110 may be interconnected to oneanother and/or to one or more other base stations 110 or network nodes(not shown) in the wireless network 100 through various types ofbackhaul interfaces such as a direct physical connection, a virtualnetwork, or the like using any suitable transport network.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,etc. A frequency may also be referred to as a carrier, a frequencychannel, etc. Each frequency may support a single RAT in a givengeographic area in order to avoid interference between wireless networksof different RATs. In some cases, NR or 5G RAT networks may be deployed.

A BS 110 may provide communication coverage for a macro cell, a picocell, a femto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs 120 with service subscription.A pico cell may cover a relatively small geographic area and may allowunrestricted access by UEs 120 with service subscription. A femto cellmay cover a relatively small geographic area (e.g., a home) and mayallow restricted access by UEs 120 having association with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in thehome, etc.). A BS 110 for a macro cell may be referred to as a macro BS110. A BS for a pico cell may be referred to as a pico BS. A BS for afemto cell may be referred to as a femto BS or a home BS. In the exampleshown in FIG. 1 , the BSs 110 a, 110 b and 110 c may be macro BSs forthe macro cells 102 a, 102 b and 102 c, respectively. The BS 110 x maybe a pico BS for a pico cell 102 x. The BSs 110 y and 110 z may be femtoBS for the femto cells 102 y and 102 z, respectively. A BS may supportone or multiple (e.g., three) cells.

The wireless network 100 may also include relay stations. A relaystation is a station that receives a transmission of data and/or otherinformation from an upstream station (e.g., a BS or a UE) and sends atransmission of the data and/or other information to a downstreamstation (e.g., a UE or a BS). A relay station may also be a UE thatrelays transmissions for other UEs. In the example shown in FIG. 1 , arelay station 110 r may communicate with the BS 110 a and a UE 120 r inorder to facilitate communication between the BS 110 a and the UE 120 r.A relay station may also be referred to as a relay BS, a relay, etc.

The wireless network 100 may be a heterogeneous network that includesBSs of different types, e.g., macro BS, pico BS, femto BS, relays, etc.These different types of BSs may have different transmit power levels,different coverage areas, and different impact on interference in thewireless network 100. For example, macro BS may have a high transmitpower level (e.g., 20 Watts) whereas pico BS, femto BS, and relays mayhave a lower transmit power level (e.g., 1 Watt).

The wireless network 100 may support synchronous or asynchronousoperation. For synchronous operation, the BSs may have similar frametiming, and transmissions from different BSs may be approximatelyaligned in time. For asynchronous operation, the BSs may have differentframe timing, and transmissions from different BSs may not be aligned intime. The techniques described herein may be used for both synchronousand asynchronous operation.

A network controller 130 may be coupled to a set of BSs and providecoordination and control for these BSs. The network controller 130 maycommunicate with the BSs 110 via a backhaul. The BSs 110 may alsocommunicate with one another, e.g., directly or indirectly via wirelessor wireline backhaul.

The UEs 120 (e.g., 120 x, 120 y, etc.) may be dispersed throughout thewireless network 100, and each UE may be stationary or mobile. A UE 120may also be referred to as a mobile station, a terminal, an accessterminal, a subscriber unit, a station, a Customer Premises Equipment(CPE), a cellular phone, a smart phone, a personal digital assistant(PDA), a wireless modem, a wireless communication device, a handhelddevice, a laptop computer, a cordless phone, a wireless local loop (WLL)station, a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, a medical device or medical equipment, a healthcare device, abiometric sensor/device, a wearable device such as a smart watch, smartclothing, smart glasses, virtual reality goggles, a smart wrist band,smart jewelry (e.g., a smart ring, a smart bracelet, etc.), anentertainment device (e.g., a music device, a video device, a satelliteradio, etc.), a vehicular component or sensor, a smart meter/sensor, arobot, a drone, industrial manufacturing equipment, a positioning device(e.g., GPS, Beidou, terrestrial), or any other suitable device that isconfigured to communicate via a wireless or wired medium. Some UEs maybe considered machine-type communication (MTC) devices or evolved MTC(eMTC) devices, which may include remote devices that may communicatewith a base station, another remote device, or some other entity.Machine type communications (MTC) may refer to communication involvingat least one remote device on at least one end of the communication andmay include forms of data communication which involve one or moreentities that do not necessarily need human interaction. MTC UEs mayinclude UEs that are capable of MTC communications with MTC serversand/or other MTC devices through Public Land Mobile Networks (PLMN), forexample. MTC and eMTC UEs include, for example, robots, drones, remotedevices, sensors, meters, monitors, cameras, location tags, etc., thatmay communicate with a BS, another device (e.g., remote device), or someother entity. A wireless node may provide, for example, connectivity foror to a network (e.g., a wide area network such as Internet or acellular network) via a wired or wireless communication link. MTC UEs,as well as other UEs, may be implemented as Internet-of-Things (IoT)devices, e.g., narrowband IoT (NB-IoT) devices. In NB IoT, the UL and DLhave higher periodicities and repetitions interval values as a UEdecodes data in extended coverage.

In FIG. 1 , a solid line with double arrows indicates desiredtransmissions between a UE and a serving BS, which is a BS designated toserve the UE on the downlink and/or uplink. A dashed line with doublearrows indicates interfering transmissions between a UE and a BS.

Certain wireless networks (e.g., LTE) utilize orthogonal frequencydivision multiplexing (OFDM) on the downlink and single-carrierfrequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDMpartition the system bandwidth into multiple (K) orthogonal subcarriers,which are also commonly referred to as tones, bins, etc. Each subcarriermay be modulated with data. In general, modulation symbols are sent inthe frequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, the spacing of the subcarriers may be 15 kHz and the minimumresource allocation (called a ‘resource block’) may be 12 subcarriers(or 180 kHz). Consequently, the nominal FFT size may be equal to 128,256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10 or 20megahertz (MHz), respectively. The system bandwidth may also bepartitioned into subbands. For example, a subband may cover 1.08 MHz(e.g., 6 resource blocks), and there may be 1, 2, 4, 8 or 16 subbandsfor system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communications systems, such as NR. NR may utilizeOFDM with a CP on the uplink and downlink and include support forhalf-duplex operation using time division duplex (TDD). A singlecomponent carrier bandwidth of 100 MHz may be supported. NR resourceblocks may span 12 sub-carriers with a sub-carrier bandwidth of 75 kHzover a 0.1 ms duration. Each radio frame may consist of 50 subframeswith a length of 10 ms. Consequently, each subframe may have a length of0.2 ms. Each subframe may indicate a link direction (e.g., DL or UL) fordata transmission and the link direction for each subframe may bedynamically switched. Each subframe may include DL/UL data as well asDL/UL control data. UL and DL subframes for NR may be as described inmore detail below with respect to FIGS. 6 and 7 . Beamforming may besupported and beam direction may be dynamically configured. MIMOtransmissions with precoding may also be supported. MIMO configurationsin the DL may support up to 8 transmit antennas with multi-layer DLtransmissions up to 8 streams and up to 2 streams per UE. Multi-layertransmissions with up to 2 streams per UE may be supported. Aggregationof multiple cells may be supported with up to 8 serving cells.Alternatively, NR may support a different air interface, other than anOFDM-based. NR networks may include entities such CUs and/or DUs.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more subordinateentities. That is, for scheduled communication, subordinate entitiesutilize resources allocated by the scheduling entity. Base stations arenot the sole entities that may function as a scheduling entity. That is,in some examples, a UE may function as a scheduling entity, schedulingresources for one or more subordinate entities (e.g., one or more otherUEs). In this example, the UE is functioning as a scheduling entity, andother UEs utilize resources scheduled by the UE for wirelesscommunication. A UE may function as a scheduling entity in apeer-to-peer (P2P) network, and/or in a mesh network. In a mesh networkexample, UEs may optionally communicate directly with one another inaddition to communicating with the scheduling entity.

Thus, in a wireless communication network with a scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As noted above, a RAN may include a CU and DUs. A NR BS (e.g., eNB, 5GNode B, Node B, transmission reception point (TRP), access point (AP),or gNB) may correspond to one or multiple BSs. NR cells can beconfigured as access cell (ACells) or data only cells (DCells). Forexample, the RAN (e.g., a central unit or distributed unit) canconfigure the cells. DCells may be cells used for carrier aggregation ordual connectivity, but not used for initial access, cellselection/reselection, or handover. In some cases DCells may nottransmit synchronization signals—in some case cases DCells may transmitSS. NR BSs may transmit downlink signals to UEs indicating the celltype. Based on the cell type indication, the UE may communicate with theNR BS. For example, the UE may determine NR BSs to consider for cellselection, access, handover, and/or measurement based on the indicatedcell type.

FIG. 2 illustrates an example logical architecture of a distributedradio access network (RAN) 200, which may be implemented in the wirelesscommunication system illustrated in FIG. 1 . A 5G access node 206 mayinclude an access node controller (ANC) 202. The ANC may be a centralunit (CU) of the distributed RAN 200. The backhaul interface to the nextgeneration core network (NG-CN) 204 may terminate at the ANC. Thebackhaul interface to neighboring next generation access nodes (NG-ANs)may terminate at the ANC. The ANC may include one or more TRPs 208(which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs,eNB, gNB, or some other term). As described above, a TRP may be usedinterchangeably with “cell.”

The TRPs 208 may be a DU. The TRPs may be connected to one ANC (ANC 202)or more than one ANC (not illustrated). For example, for RAN sharing,radio as a service (RaaS), and service specific AND deployments, the TRPmay be connected to more than one ANC. A TRP may include one or moreantenna ports. The TRPs may be configured to individually (e.g., dynamicselection) or jointly (e.g., joint transmission) serve traffic to a UE.

The local architecture 200 may be used to illustrate fronthauldefinition. The architecture may be defined that support fronthaulingsolutions across different deployment types. For example, thearchitecture may be based on transmit network capabilities (e.g.,bandwidth, latency, and/or jitter).

The architecture may share features and/or components with LTE.According to aspects, the next generation AN (NG-AN) 210 may supportdual connectivity with NR. The NG-AN may share a common fronthaul forLTE and NR.

The architecture may enable cooperation between and among TRPs 208. Forexample, cooperation may be preset within a TRP and/or across TRPs viathe ANC 202. According to aspects, no inter-TRP interface may beneeded/present.

According to aspects, a dynamic configuration of split logical functionsmay be present within the architecture 200. As will be described in moredetail with reference to FIG. 5 , the Radio Resource Control (RRC)layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control(RLC) layer, Medium Access Control (MAC) layer, and a Physical (PHY)layers may be adaptably placed at the DU or CU (e.g., TRP or ANC,respectively). According to certain aspects, a BS may include a centralunit (CU) (e.g., ANC 202) and/or one or more distributed units (e.g.,one or more TRPs 208).

FIG. 3 illustrates an example physical architecture of a distributed RAN300, according to aspects of the present disclosure. A centralized corenetwork unit (C-CU) 302 may host core network functions. The C-CU may becentrally deployed. C-CU functionality may be offloaded (e.g., toadvanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 304 may host one or more ANC functions.Optionally, the C-RU may host core network functions locally. The C-RUmay have distributed deployment. The C-RU may be closer to the networkedge.

A DU 306 may host one or more TRPs (edge node (EN), an edge unit (EU), aradio head (RH), a smart radio head (SRH), or the like). The DU may belocated at edges of the network with radio frequency (RF) functionality.

FIG. 4 illustrates example components of the BS 110 and UE 120illustrated in FIG. 1 , which may be used to implement aspects of thepresent disclosure. As described above, the BS may include a TRP. One ormore components of the BS 110 and UE 120 may be used to practice aspectsof the present disclosure. For example, antennas 452, processors 466,458, 464, and/or controller/processor 480 of the UE 120 and/or antennas434, processors 460, 420, 438, and/or controller/processor 440 of the BS110 may be used to perform the operations described herein andillustrated with reference to FIGS. 6-13 .

FIG. 4 shows a block diagram of a design of a BS 110 and a UE 120, whichmay be one of the BSs and one of the UEs in FIG. 1 . For a restrictedassociation scenario, the base station 110 may be the macro BS 110 c inFIG. 1 , and the UE 120 may be the UE 120 y. The base station 110 mayalso be a base station of some other type. The base station 110 may beequipped with antennas 434 a through 434 t, and the UE 120 may beequipped with antennas 452 a through 452 r.

At the base station 110, a transmit processor 420 may receive data froma data source 412 and control information from a controller/processor440. The control information may be for the Physical Broadcast Channel(PBCH), Physical Control Format Indicator Channel (PCFICH), PhysicalHybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel(PDCCH), etc. The data may be for the Physical Downlink Shared Channel(PDSCH), etc. The processor 420 may process (e.g., encode and symbolmap) the data and control information to obtain data symbols and controlsymbols, respectively. The processor 420 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 430 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) 432 a through 432t. For example, the TX MIMO processor 430 may perform certain aspectsdescribed herein for RS multiplexing. Each modulator 432 may process arespective output symbol stream (e.g., for OFDM, etc.) to obtain anoutput sample stream. Each modulator 432 may further process (e.g.,convert to analog, amplify, filter, and upconvert) the output samplestream to obtain a downlink signal. Downlink signals from modulators 432a through 432 t may be transmitted via the antennas 434 a through 434 t,respectively.

At the UE 120, the antennas 452 a through 452 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) 454 a through 454 r, respectively. Eachdemodulator 454 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 454 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 456 may obtainreceived symbols from all the demodulators 454 a through 454 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. For example, MIMO detector 456 may provide detected RStransmitted using techniques described herein. A receive processor 458may process (e.g., demodulate, deinterleave, and decode) the detectedsymbols, provide decoded data for the UE 120 to a data sink 460, andprovide decoded control information to a controller/processor 480.According to one or more cases, CoMP aspects can include providing theantennas, as well as some Tx/Rx functionalities, such that they residein distributed units. For example, some Tx/Rx processings can be done inthe central unit, while other processing can be done at the distributedunits. For example, in accordance with one or more aspects as shown inthe diagram, the BS mod/demod 432 may be in the distributed units.

On the uplink, at the UE 120, a transmit processor 464 may receive andprocess data (e.g., for the Physical Uplink Shared Channel (PUSCH)) froma data source 462 and control information (e.g., for the Physical UplinkControl Channel (PUCCH) from the controller/processor 480. The transmitprocessor 464 may also generate reference symbols for a referencesignal. The symbols from the transmit processor 464 may be precoded by aTX MIMO processor 466 if applicable, further processed by thedemodulators 454 a through 454 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 110. At the BS 110, the uplink signalsfrom the UE 120 may be received by the antennas 434, processed by themodulators 432, detected by a MIMO detector 436 if applicable, andfurther processed by a receive processor 438 to obtain decoded data andcontrol information sent by the UE 120. The receive processor 438 mayprovide the decoded data to a data sink 439 and the decoded controlinformation to the controller/processor 440.

The controllers/processors 440 and 480 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 440 and/orother processors and modules at the base station 110 may perform ordirect the processes for the techniques described herein. The processor480 and/or other processors and modules at the UE 120 may also performor direct processes for the techniques described herein. The memories442 and 482 may store data and program codes for the BS 110 and the UE120, respectively. A scheduler 444 may schedule UEs for datatransmission on the downlink and/or uplink.

FIG. 5A is a diagram 500A showing an example of a DL-centric subframe.The DL-centric subframe may include a control portion 502A. The controlportion 502A may exist in the initial or beginning portion of theDL-centric subframe. The control portion 502A may include variousscheduling information and/or control information corresponding tovarious portions of the DL-centric subframe. In some configurations, thecontrol portion 502A may be a physical DL control channel (PDCCH), asindicated in FIG. 5A. The DL-centric subframe may also include a DL dataportion 504A. The DL data portion 504A may sometimes be referred to asthe payload of the DL-centric subframe. The DL data portion 504A mayinclude the communication resources utilized to communicate DL data fromthe scheduling entity 202 (e.g., eNB, BS, Node B, 5G NB, TRP, gNB, etc.)to the subordinate entity, e.g., UE 120. In some configurations, the DLdata portion 504A may be a physical DL shared channel (PDSCH). TheDL-centric subframe may also include a common UL portion 506A. Thecommon UL portion 506A may sometimes be referred to as an UL burst, acommon UL burst, and/or various other suitable terms. The common ULportion 506A may include feedback information corresponding to variousother portions of the DL-centric subframe. For example, the common ULportion 506 may include feedback information corresponding to thecontrol portion 502A. Non-limiting examples of feedback information mayinclude an ACK signal, a NACK signal, a HARQ indicator, and/or variousother suitable types of information. The common UL portion 506A mayinclude additional or alternative information, such as informationpertaining to random access channel (RACH) procedures, schedulingrequests (SRs), sounding reference signals (SRS) and various othersuitable types of information. As illustrated in FIG. 5A, the end of theDL data portion 504A may be separated in time from the beginning of thecommon UL portion 506A. This time separation may sometimes be referredto as a gap, a guard period, a guard interval, and/or various othersuitable terms. This separation provides time for the switchover from DLcommunication (e.g., reception operation by the subordinate entity,e.g., UE 120) to UL communication (e.g., transmission by the subordinateentity e.g., UE 120). One of ordinary skill in the art will understand,however, that the foregoing is merely one example of a DL-centricsubframe and alternative structures having similar features may existwithout necessarily deviating from the aspects described herein.

FIG. 5B is a diagram 500B showing an example of an UL-centric subframe.The UL-centric subframe may include a control portion 502B. The controlportion 502B may exist in the initial or beginning portion of theUL-centric subframe. The control portion 502B in FIG. 5B may be similarto the control portion 502A described above with reference to FIG. 5A.The UL-centric subframe may also include an UL data portion 504B. The ULdata portion 504B may sometimes be referred to as the payload of theUL-centric subframe. The UL portion may refer to the communicationresources utilized to communicate UL data from the subordinate entity,e.g., UE 120 to the scheduling entity 202 (e.g., eNB). In someconfigurations, the control portion 502B may be a physical UL sharedchannel (PUSCH). As illustrated in FIG. 5B, the end of the controlportion 502B may be separated in time from the beginning of the UL dataportion 504B. This time separation may sometimes be referred to as agap, guard period, guard interval, and/or various other suitable terms.This separation provides time for the switchover from DL communication(e.g., reception operation by the scheduling entity 202) to ULcommunication (e.g., transmission by the scheduling entity 202). TheUL-centric subframe may also include a common UL portion 506B. Thecommon UL portion 506B in FIG. 5B may be similar to the common ULportion 506A described above with reference to FIG. 5A. The common ULportion 506B may additionally or alternatively include informationpertaining to channel quality indicator (CQI), sounding referencesignals (SRSs), and various other suitable types of information. One ofordinary skill in the art will understand that the foregoing is merelyone example of an UL-centric subframe and alternative structures havingsimilar features may exist without necessarily deviating from theaspects described herein. In summary, a UL centric subframe may be usedfor transmitting UL data from one or more mobile stations to a basestation, and a DL centric subframe may be used for transmitting DL datafrom the base station to the one or more mobile stations. In oneexample, a frame may include both UL centric subframes and DL centricsubframes. In this example, the ratio of UL centric subframes to DLsubframes in a frame may be dynamically adjusted based on the amount ofUL data and the amount of DL data that need to be transmitted. Forexample, if there is more UL data, then the ratio of UL centricsubframes to DL subframes may be increased. Conversely, if there is moreDL data, then the ratio of UL centric subframes to DL subframes may bedecreased.

Resource Assignment in NR-SS

A resource element (RE) may cover one subcarrier in one symbol periodand may be used to send one modulation symbol, which may be a real or acomplex value. Resource elements may be grouped into physical resourceblocks (PRB). In LTE, a PRB is a time/frequency resource of 180 kHz (12subcarriers) by 0.5 msec or 1 slot. Each slot has 6 or 7 symbols, 6 forextended CP and 7 symbols for normal CP. Physical resource blocks (PRB)may be grouped into larger radio resources called Resource Block Groups(RBG). NR may have different subcarrier spacing from LTE. Hence, the PRBmay span a different frequency bandwidth.

The way in which the scheduler allocates resource blocks for eachtransmission is specified by a Resource Allocation Type. Using a stringof a bit map (bitstream) provides a way to give the maximum flexibilityof allocating resource blocks where each bit represents one of theresource blocks. Although this approach may result in maximumflexibility, it may create too much overhead (e.g., along bit map) alongwith a complicated way to allocate the resources. So a couple ofresource allocation types were introduced by LTE to address thisproblem. A predefined process is used by each of the resource allocationtypes. In LTE there are three different resource allocation types,Resource Allocation Type 0, 1, 2. See Table 1 below.

TABLE 1 DCI Format Type Memo 1 Type 0 or Type 1 Determined by resourceallocation header field 1A Type 2 1B Type 2 1C Type 2 1D Type 2 2 Type 0or Type 1 Determined by resource allocation header field 2A Type 0 orType 1 Determined by resource allocation field

Note the Table 1 list is the current definition of Resource AllocationTypes in LTE.

Different feedback and resource granularities, in multiples of PRBs canbe used with NR. In LTE, for a system bandwidth of 10 MHz, the 3GPPstandard specifies a resource unit granularity for a RBG size of 3 PRBs,that specifies the smallest amount of resources the BS scheduler canassign to a UE (in resource allocation type 0). In NR, the RBG size maybe different from LTE.

Resource Allocation Type 0 allocates resources by first dividingresource blocks into multiples of resource block groups (RBG). Thenumber of physical resource blocks in each resource block group (RBG)varies with the system bandwidth. The RBG size will vary with the systembandwidth. The relationship between RBG size (the number of physicalresource blocks (PRB) in a resource block group (RBG)) and the systembandwidth in LTE is shown in Table 2 below.

TABLE 2 System Bandwidth (MHz) RBG Size (in PRBs) 1.4 1 3 2 5 2 10 3 154 20 4

Like LTE discussed above, NR agreed to support different RBG sizesdepending on the configured bandwidth part (BWP), where RGB size ismeasured by the number of PRBs and BWP is the part of the system BW thatthe UE will be using. UEs with different bandwidth part (BWP)configuration may have different RBG size. This allows UE with smallerBWP to have more precise or finer RBG granularity in signalling orsmaller RBG size in terms of PRBs, while UEs with larger BWP may have acoarser granularity in RBG size or larger RBG size in terms of PRBs. Asshown in Table 3 below, for a system BW of 1.4 MHz, the granularity is 1PRB, while for a system BW of 20 MHz, the granularity is 4 PRB. This isone example of RBG size (or granularity in PRBs) vs. configuredbandwidth part (BWP).

TABLE 3 Configured BWP (MHz) RBG Size (in PRBs) 1.4 1 3 2 5 2 10 3 15 420 4

A UE may open up (or use) its RF resources based on the BWPconfiguration for better power consumption. For example, in an 80 MHzsystem, the UE may use less than the 80 MHz to save power by using only20 MHz or 40 MHz, where the system can have up to 80 Mhz bandwidth. TheBWP is expected to be contiguous in NR configuration (to minimize the RFcost). For example, if a UE uses 20 MHz, only one filter may be used iftwo 10 MHz channels are contiguous, while two filters may have to beused if the two 10 MHz channels are located at opposite ends of the 80MHz spectrum. A physical resource block group (RBG) has PHY/MACparameters (such as active DFT-spreading, TTI length, tight/relaxedtime-frequency alignment, or waveform parameters). One reason NR canprovide a configurable air interface is because different RBGs may havedifferent numerologies and parameters. For example, 720 kHz or 1440 kHzin frequency and 1 ms in time (which corresponds to 12 subcarriers and14 symbols) are two example sizes for resource block groups (RBG). TTI(Transmission Time Interval) is the smallest scheduling time interval inLTE.

In NR-SS, for each transmission opportunity (TXOP), a node may be ableto access the medium with a successful LBT outcome and reserve onechannel or multiple channels depending on the medium sensing. That is,if channels are sensed by the UE during a listen before talk (LBT)procedure to be currently occupied by another node, e.g., a WiFi node,the UE can't use them to transmit information. (A transmissionopportunity (TXOP) is granted by an access point to a terminal andrefers to duration of time during which the station can send frames).For example, in a 80 MHz system, a node may occupy 80, 60, 40, or 20 MHzdepending on how many channels the neighbor WiFi nodes occupy, whereeach WiFi channel access is defined to be 20 MHz. In addition, thechannels occupied by WiFi nodes may not be contiguous within 80 MHz.

The UE or gNB does medium sensing to coexist with WiFi. A node (eitherUE or gNB) can't use a channel without first having a successful LBTprocedure for that channel. In this example, if the BWP of the node is80 MHz, the node may use RF resources for the entire 80 MHz and couldtransmit on the entire 80 MHz if it can access the medium with asuccessful LBT outcome and reserve all four 20 MHz channels. However, ifthe result of the LBT procedure is a 20 MHz channel is unoccupied, theRBG size can be reduced. Because of medium sensing, the RBG size can beadjusted once the medium occupancy is known.

In one example, the method and apparatus has a coarser (or larger) RBGsize when a node is able to access the medium with a successful LBToutcome and reserves more channels for a UE, while having a finer (orsmaller) RBG granularity when a node is able to access the medium with asuccessful LBT outcome and reserves less channels with RBG basedresource allocation. In a first example, RBG size can be dynamic anddepend on the medium occupation, that is, what channels are used by theUE to transmit and/or receive information. Resource allocation (RA) in aPDCCH points to the occupied channel. For example, if the node is ableto access the medium with a successful LBT outcome and reserves thesecond channel, the first assigned RBG in PDCCH, RBG0 in PDCCH, is foundwithin the second channel since the first channel is not used oroccupied. Since only 20 MHz is occupied by the gNB, a finer RBG sizewill be used as opposed to the case where gNB is occupying all 80 MHz.Depending on the medium occupancy of the gNB, the RBG size candynamically change.

The data carried on the PDCCH can be referred to as downlink controlinformation (DCI). Multiple wireless devices can be scheduled in onesubframe of a radio frame. Therefore, multiple DCI messages can be sentusing multiple PDCCHs. The DCI information in a PDCCH can be transmittedusing one or more control channel elements (CCE). A CCE can be comprisedof a group of resource element groups (REGs). A legacy CCE in LTE caninclude up to nine REGs. Each legacy REG can be comprised of fourresource elements (REs). Each resource element can include two bits ofinformation when quadrature modulation is used. Therefore, a legacy CCEcan include up to 72 bits of information. When more than 72 bits ofinformation are used to convey the DCI message, multiple CCEs can beemployed. The use of multiple CCEs can be referred to as an aggregationlevel. In one example, the aggregation levels can be defined as 1, 2, 4or 8 consecutive CCEs allocated to one legacy PDCCH.

In a first solution, the gNB sends information on a separate physicallayer channel (i.e., L1 channel) to the UE that so much bandwidth isoccupied along with the RBG granularity in PRBs, where the L1 channel isthe over the air physical layer. More specifically, the gNB uses aseparate signaling carried on the L1 channel to indicate to the UE thatit occupies the medium along with the RBG size. For example, a node mayindicate that it has medium access on an 80 MHz channel with an RBG sizebeing X RB, or it may indicate that it has medium access on a 20 MHzchannel with an RBG size being Y RB. In one example, Y RB is smaller insize than X RB. For example, when a gNB occupies 80 MHz, it uses an RBGsize of 16 PRB, while when it occupies 20 MHz, it uses RBG size of 4PRB. The separate L1 layer can carry channels common to the gNB or agroup of UEs associated with the gNB like the PCFICH as opposed to beingUE specific like the PDCCH. The UE may also be configured with a channeland an RBG size using a message from the RRC called the RRCconfiguration message as shown in FIG. 6 . The actual RBG used forresource allocation (RA) for each UE can be min (RRC RBG, L1 RBG), whereRRC RBG is the RBG size configured in the RRC layer and L1 RBG is theRBG size signaled on the L1 layer.

To improve robustness, such information carried on the L1 layer can betransmitted in the first slot of the TXOP and repeated in the subsequentslots of the TXOP.

In a second solution, a node indicates the medium occupation ininformation carried on a separate common L1 channel, but the RBG size isnot signaled. Instead, there is an implicit mapping between the RBG sizeand the medium occupation or the configured BWP. Such implicit mappingcan be either predefined or configured to UE. In this example, the UE ispreconfigured with a mapping of medium occupation to RBG size. FIG. 7illustrates an exemplary mapping of medium occupation to RBG size forone to four channels, where 20 MHz equals one channel, 40 MHz equals twochannels, 60 MHz equals three channels and 80 MHz equals four channelsand the corresponding RBG size is RBGX1, RBGX2, RBGX3, and RBGX4. Forexample, if the RBG size is X PRB, the node can transmit on an 80 MHz,channel, while if the RBG size is Y PRB, the node transmits on a 20 MHzchannel. For example, when a gNB occupies 80 MHz, it uses an RBG size of16 PRB, while when it occupies 20 MHz, it uses RBG size of 4 PRB. Notethat the mapping between the channel occupation (or configured bandwidth(BWP)) to RBG size can be UE-specific.

In a third solution, a node indicates the medium occupation in a UEspecific signaling channel for a UE like the C-RNTI PDCCH. A separatechannel is not used to signal the medium occupation since the PDCCH hasa field that can be used to carry resource allocation. However, like thesecond solution, there is an implicit or predefined mapping between thechannel occupation (or configured bandwidth (BWP)) and the RBG size. TheUE interprets the RBG size based on the medium occupation accordingly.The implicit mapping is similar to the second solution. So whereasbefore a common signal carried on the L1 layer was used to convey mediumoccupation to configure a UE with a BWP, here a UE specific PDCCH isused. In both solutions RBG size is implicitly mapped to the mediumoccupation. In one example, the UE can be preconfigured with the tableshown in FIG. 7 . Also, here a bitmap may be used. For example, with an80 MHz system bandwidth comprising four 20 MHz channels, a 4-bit bitmapmay be introduced at the PDCCH. gNB indicates the medium occupation viathe bitmap and, the UE interprets the RBG size based on the mediumoccupation. See FIG. 8 , which discloses using a bitmap to configure aUE with a channel and an RBG size. In one example, at least one bit inthe bitmap represents one or more RBGs. If the resource allocation isRBG based, the bitmap may indicate the first and the last RBG that isoccupied by the UE.

An additional guard band may be used if a node is able to access themedium with a successful LBT outcome and reserves some, but not allchannels, such that not all of the BW is occupied. For example, if anode reserves the 20 MHz channel, but not the 40 MHz, 60 MHz, or 80 MHzchannels, it may perform better by adding additional guard band on eachside of the 20 MHz bandwidth to accommodate the adjacent channelleakage-power ratio (ACLR). Power that leaks from a transmitted signalinto adjacent channels in a digital communication system such as LTE isreferred to as ACLR. It can impair system performance by interferingwith transmissions in neighboring channels which are not occupied by thecurrent node. Thus, system transmitters perform within specified limitsto avoid ACLR. On the other hand, the 20 Mhz channel may not use anyguard band if a node gains access to all the channels which in oneexample is the four 20 MHz channels. In this example, the UE occupiesthe entire bandwidth which is 80 MHz so adjacent channel leakage acrosseach 20 MHz channel is not a concern.

In one example, an RBG grid based on absolute PRB0 with respect to thesystem bandwidth is used. Assuming the system BW is 80 MHz, the PRBindex can be defFfig. 9ined to be consistent with the 80 MHz even if thenode occupies less than the full 80 MHz system BW, e.g., it occupiesonly one of the 20 MHz channels. In this case the PRB index is stillfollowed and the PRB index is defined according to the 80 MHz case eventhough a fraction of the 80 MHz is occupied. The UE can translate theassigned RB/RBGs/interlaces to the occupied channel. The RBG grid basedon system bandwidth may not align with each channel. Depending on theRBG size, the PRBs across different channels may fall into the same RBG.For example, FIG. 9A illustrates an allocation of PRBs and RBGs to 4channels. In FIG. 9A, which will be discussed in further detail below,one RBG (i.e., the RBG0 signaled in PDCCH) consists of 4 PRBs. UE cantranslate RBG0 in PDCCH, together with medium occupancy information toPRBs 48, 49, 50 and 51. Here the first 2 PRBs of RBG0, PRBs 48 and 49belong to Channel 0, while the last 2 PRBs of RBG 0 (PRBs 50 and 51),belong to Channel 1. In addition, the PRBs in the guard band may fallinto the RBG as well when a guard band is used as shown with PRBs 49 and50.

In one example, a guard band is configured for each channel. The UEswill calculate the transport block size (TBS) using the usable RBsfalling into the occupied channel and rate match accordingly. Data fromthe upper layer (or MAC layer) received by the physical layer in an LTEsystem is called a transport block. In one example, the number ofPhysical Resource Blocks (N_(PRB)) and the MCS (Modulation and CodingScheme) are used to compute the transport block size.

As stated above, the RBG size depends on the medium occupancy but thePRG may be defined with respect to the system bandwidth. The larger themedium occupancy, the greater the number of PRB units used in an RBG.For example, when an RBG size is 2 physical resource blocks (PRB), RBG 0consists of PRB 0 and PRB1, and RBG 50 consists of PRB 100 and PRB 101.In another example, when RBG size is 3 RBs, RBG 1 consists of PRB 0,PRB1 and PRB2 and RBG 50 consists of PRB 150, PRB 151 and PRB 152

In one example, the guard band can be defined in the unit of PRBs. Whenmini-PRBs are used, the guard band can be measured in units ofmini-PRBs. When a node is not able to access the medium with asuccessful LBT outcome and reserves a channel, the RBGs fully in thechannel (including the guard band on either left or right when used) arenot counted in the actual resource allocation. A PRB consists of 12subcarriers while a mini-PRB stands for a fraction of RB which consistsof less than 12 PRBs. For example, a mini-PRB may consist of 4sub-carriers.

In one example, assume each channel has 50 PRBs. If the gNB allocateschannel 1 and channel 3 (and channels 2 and 4 are not allocated) and thecorresponding RBG size is 4 RB, then RBG 0 would comprise of PRBs 48-51as the first 12 RBGs (i.e., which is the first 48 PRBs, PRB 0 thru 47since each PRG=4 PRBs) are not counted. The first 12 RBGs (along withPRBs 0-47) are not counted because the gNB does not occupy channel 0.Thus, RBG 0 signaled in the PDCCH, the starting RBG is effectivelytranslated from PRBs 0-3 to PRBs 48-51.

When a RBG partially falls into a reserved channel (excluding guard bandwhen used), the usable PRBs in the RBG may be utilized. In the exampleshown in FIG. 9A, the 13^(th) RBG containing PRBs 48-51 is the first RBGwith usable PRBs which in this case is PRB 51. PRB 48 is not usablebecause it falls in an unoccupied channel and PRBs 49 and 50 are notusable because they fall into the guard band. The UE begins countingPRBs when there is overlap with an occupied channel, in this casechannel 1. So RBG 0 has effectively been translated to RBG 12 (i.e., the13^(th) RBG) by the UE. The remaining RBGs are sequentially numbered forthe resource allocation (RA) field.

As stated above, FIG. 9A illustrates an allocation of PRBs and RBGs to 4channels, channels 0 thru 3, where 50 PRBs per channel are allocated,along with an RBG size of 4 PRBs. Channel 0 spans PRBs 0 to 49. Channel1 is occupied by PRBs 50 to 99. Channel 2 spans PRBs 100 to 149, andchannel 3 is occupied by PRBs 150 to 199. Resource allocation type 0uses a bitmap to allocate the resources and each bit represents one RBG.The RBG grid is based on the number of PRBs in an RBG corresponding tosystem bandwidth and may include PRBs from adjacent channels as well asthe guard band. If a UE is assigned those RBGs, PRBs from adjacentchannels as well as the guard band, it will use the usable PRBs fallinginto the indicated channel to rate match as well as calculate transportblock size (TBS) accordingly. In the present example, the node is ableto transmit on channel 1 and channel 3, where the RBG is assumed to be 4PRBs. The node does not have access to channel 0 or channel 2 and cannottransmit the true PRB0 or RBG0 both of which would be located in channel0 using the entire system BW, but has been translated to PRBs 48-51since channel 0 is not occupied by the UE. In the PDCCH, the resourceassignment RBG0 tells the UE about the transmission on actual RBG 12which comprises PRBs 48-51. The PDCCH indicates PRB 51 will be used fortransmission as explained below.

Here the UE interprets the RBG0 signaled in PDCCH to the RBG 12 as thisis the first RBG which overlaps with channel 1 with useful RBs. Butsince PRB 48 and 49 fall into channel 0 and PRB 50 is used for a guardband, se the UE knows only PRB 51 can be used to transmit. Thus, the UEwill only use PRB 51 to transmit if RBG0 is indicated as occupied andskip PRBs 48-50. This saves resource assignment overhead compared tosignaling PRB 51 or RBG 12 explicitly in PDCCH.

Previously, an RBG based resource allocation was discussed. With RBGbased resource allocation, a bit can be assigned to one or more RBGswhich may be used to indicate whether an RBG is assigned to the UE ornot. Alternatively, a compact resource allocation may also be used inNR-SS. With compact resource allocation, a gNB indicates the startingPRB, RBG, or interlace as well as the number of occupiedRBs/RBGs/Interlaces that follow to reduce the RA overhead as opposed toRBG based resource allocation by using less bits.

When the channel access is not contiguous, for the compact RA assignmenta gNB may indicate a starting point as well as the number of occupiedPRBs, RBGs, or Interlaces per channel that follow that staring point.This could result into a large RA overhead. The resource allocation inan LAA system differs from how resources are allocated with LTE. Aninterlace composed of ten resource blocks equally spaced in frequencywithin a 20 MHz frequency bandwidth is the basic unit of resourceallocation for LTE unlicensed channels.

The present example uses a single starting point of PRBs, RBG, orInterlaces and fixed number of PRBs, RBG, or Interlaces following thestarting point irrespective of the channel access. This means that theassignment, from the signaling perspective, may span all the channelswithout necessarily being able to access or occupy some of the channels.The UE may automatically skip PRBs, RBGs or interlaces in channels thatgNB does not have access on along with automatically skipping PRBs foundin guard bands. Thus, the PRBs, RBGs, or interlaces in the guard band aswell as the unoccupied channels are automatically skipped.

RBs in guard bands and unoccupied channels are automatically skippedwhen using compact resource allocation (RA). So the present compactmethod of allocating resources has a single starting point which can bea PRB, an RBG, or an interlace, along with how many PRBs, RBGs, orinterlaces are going to be occupied This applies to RAs with or withouthopping. FIG. 9B illustrates an example of this method of allocation. Inthe illustrated example, channels 0 and 3 are assumed to be occupied bythe UE. In the figure shown, there are 50 PRBs per channel, along withan RBG size of 4 PRBs. Channel 0 is occupied by PRBs 0 to 49 and channel3 is occupied by PRBs 150 to 199. A gNB reserves channels 0 and 3 andassigns a UE with a starting PRB equal to PRB 0 along with a total PRBnumber of 52 PRBs in this example. In other examples, the total PRBnumber can be different than 52. In this example, the UE has alreadybeen signaled by the gNB that it has access on channels 0 and 3. If theUE receives an assignment from the gNB where the starting PRB is PRB 0and the transmission occupies 52 PRBs, it will know that thetransmission actually spans PRBs 0 to 48 (49 PRBs located in channel 0)as well as PRB 151, 152 and 153 (3 PRBs located in channel 3) whileskipping all the PRBs in between that it does not occupy like PRBs inchannels 1 and 2, PRBs 50 to 149, along with PRBs found in guard bandslike PRB 49 and PRB 50. The UE will automatically skip the RBs in theguard band as well as the RBs in channels 1 and 2 to obtain the actualRBs usable for transmission or reception. PRB 49 and PRB 150 are skippedbecause they are guard bands (GB) for channels 0 and 3 respectfully.PRBs 50 to 149 are skipped because they are located in channels 1 and 2which are not occupied by the UE. To get to 52 occupiable PRBs, PRBs 0to 48 in channel 1 are used along with PRBs 151 to 153 in channel 3.This allocation starts with PRB 0 and spans a total of 52 usable PRBs.Thus, the resources are allocated by indicating starting PRB 0 and alongwith indicating a length of 52 usable PRBs. This is less overhead thanindicating a starting point of PRBs, RBG, or interlaces and a length ofPRBs, RBG, or interlaces for each channel with medium access.

FIG. 10A is a flowchart of the steps taken by a gNB to indicate mediumoccupation along with RBG size to a UE. The TRPs 208 shown in FIG. 2 isan example of the gNB. Initially, a gNB allocates physical resourceblocks for a UE (step 1005). Then the gNB determines if the mediumoccupancy has changed (step 1010). The output of step 1010 is Yes if themedium occupancy has changed and No if it hasn't. So if the answer tostep 1010 is Yes, the medium occupancy has changed, anotherdetermination is made in step 1015 whether the medium occupancy hasgotten larger or smaller, i.e., Yes to step 1015 it has gotten larger orNo to step 1015 the medium occupancy has gotten smaller. If the answerto step 1015 is Yes, the medium occupancy has gotten larger, a coarserRBG size is assigned to the UE (step 1020 in FIG. 10A) If the answer tostep 1015 is No, the medium occupancy has gotten smaller, a finer RBGgranularity is assigned to the UE (step 1025 in FIG. 10A).

Next, the BS determines whether it can occupy all channels or not (step1027). If the answer is No it is not fully occupied, i.e., the gNBoccupies some, but not all channels or bandwidth such that not all ofthe BW is occupied, an additional guard band is used around the occupiedchannels (see step 1035). If the answer is Yes, the BW is fullyoccupied, no extra guard band is assigned. Last in step 1040, the gNBcan send information on an indicator, or signal, to the U,E indicatingmedium occupation and RBG size. In another example, the RBG size couldbe implicitly determined and not signaled dynamically.

FIG. 10B is a flowchart of the steps taken by a UE to receive mediumoccupation along with RBG size from a gNB. The UEs 120 shown in FIG. 1is an example of the UE. Initially, a UE receives information from a gNBcomprising medium occupation and physical resource block group (RBG)allocated to it by a gNB (step 1055). Then the UE receives informationfrom the gNB if the medium occupancy has changed (step 1060). The outputof step 1060 is Yes if the medium occupancy has changed and No if ithasn't. So if the answer to step 1060 is Yes, the medium occupancy haschanged, the UE finds out in step 1065 whether the medium occupancy hasgotten larger or smaller, i.e., Yes to step 1065 it has gotten larger orNo to step 1065 the medium occupancy has gotten smaller. If the answerto step 1065 is Yes, the medium occupancy has gotten larger, a coarsersize is assigned to the RBG and received by the UE (step 1070 in FIG.10B) If the answer to step 1065 is No, the medium occupancy has gottensmaller, a finer granularity is assigned to the RBG and received by theUE (step 1075 in FIG. 10B).

Next, the UE is informed whether all channels are occupied or not (step1077). If the answer is No they are not fully occupied, i.e., the BSoccupies some, but not all channels or bandwidth such that not all ofthe BW is occupied, the UE receives information that an additional guardband is assigned around the occupied channels (see step 1085). If theanswer is Yes, the BW is fully occupied, no extra guard band isassigned. Last in step 1090, the UE receives information on anindicator, or a signal, from the gNB indicating medium occupation andRBG size. In another example, the RBG size could be implicitlydetermined and not signaled dynamically.

A compact RA indication and medium occupation index may be sentseparately or sent using joint coding. Joint coding may further helpreduce the number of bits in some cases and reduce RA overhead.

In the example with 4 channels, 20/40/60/80 MHz, has a total of 200PRBS, where each channel has 50 PRBs. A starting PRB can be anywhereamong the 200 PRBs, PRB 0 to PRB 199 and the length can be anywhere from1 to 199 PRBs. A bitmap may be used for a medium occupation index, withthe bitmap using 4 bits.

If the resource allocation is not jointly coded and sent for all 4channels, each channel having N physical resource blocks (N PRBs), thenceil(log 2 (4NRB*(4NRB+1)/2)) bits would be used for compact RAindication (assuming 1 RB granularity in the allocation) using the RIVbased mapping. In this example, each channel may have 50 PRBs so N=50.

One example of joint coding would be to indicate a starting PRB in thefirst allocated channel and the ending PRB in the last allocatedchannel. Also, medium occupancy on the first and last allocated channel.This would use ceil(log 2 (NRB)+log 2(NRB)) bits. With N=50, log 2(50)=5.64 and log 2 (NRB)+log 2(NRB) bits=5.64+5.64=11.28 bits, which isaround 3 bits less than using separate coding. In FIG. 9B, the startingPRB is PRB 0 in channel 0 and the ending PRB is the 4^(th) PRB inchannel 3 which is PRB 153. So log 2 (NRB) bits are used to indicate thestarting PRB in channel 0 and log 2(NRB) bits are used to indicate theending PRB in channel 3. And the UE has already been indicated with themedium occupancy information so it knows that the starting PRB points tochannel 0 and the ending PRB points to channel 3. So the mediumoccupancy between the starting and ending PRBs/RBGs/Interlaces are alsoknown to the UE.

FIG. 11A is a flowchart of exemplary steps taken to reduce resourceallocation (RA) overhead. In step 1110, the UE receives a starting PRB,RBG, or interlace from a gNB in one example. In step 1120, thetransmission received by the UE spans a number of the RBs, RBGs, orinterlaces across multiple channels including those channels withoutmultiple access, while automatically skipping PRBs, RBGs, or interlacesin the guard band and in unoccupied channels. Overhead is reducedbecause the number of PRBs, RBGs, or interlaces transmitted to the UE isreduced. FIG. 11B is a flowchart of exemplary steps taken to reduceresource allocation overhead by joint coding a resource allocation (RA)indication and a medium occupation index. In step 1140 the UE receives astarting PRB in a first allocated channel and an ending PRB in a lastallocated channel from the gNB. So instead of receiving informationconcerning all channels, it receives a starting PRB in a first allocatedchannel and an ending PRB in a last allocated channel, thereby reducingoverhead. In step 1150, the UE receives a medium occupancy between thestarting PRB and the ending PRB from the gNB. This received informationis used by the UE to determine which RBs, RBGs, or interlaces to use andto skip unoccupied PRBs, RBGs, or interlaces.

Due to power spectral density (PSD) limitations, an interlaced channelstructure is used in the unlicensed spectrum for the UE to utilize powermore efficiently.

In addition, SC-FDM could be used in UL for a power limited UE due tothe better PAPR (peak-to-average power ratio) associated with SC-FDMwaveform compared to OFDM waveform.

FIG. 12A shows multiple interlaces with multiple equally spaced PRBs,such as a first interlace of PRBs, interlace 0, and a second interlaceof PRBs, interlace 1. An interlace may include multiple PRBs that spreadthroughout the Component Carrier system bandwidth. For example, for 20MHz bandwidth, in some deployments, there are 100 PRBs (e.g., PRB #0through PRB 99). In some examples, the first interlace of PRBs,interlace 0, may include RB #0, 10, 20, . . . 90, the second interlaceof RBs, interlace 1 may include RB #1, 11, 21, . . . 91, and so on. Witha first example, an interlace structure is defined for each channel.(Excluding the potential guard band. The guard band is excluded becauseif it is included, the UE may not be able to check out the medium). Aninterlace is composed of N physical resource blocks (PRB) equally spacedin frequency. In one example, there are equally spaced in frequency PRBson an interlace for a channel. In the 80 MHz system discussed earlier,the channel could be 20 MHz, 40 MHz, 60 MHz, or 80 MHz. Here there is acluster of interlaces, interlace 0 and interlace 1, with PRBs spacedevery 10 PRBs. In FIG. 12B, interlace 1 has PRBs that are spaced every10 PRBs. However, with multiple channels, the clusters may not beequally spaced due to the guard bands. So its preferred that theinterlace assignment does not go beyond one interlace per channel. Ifthe UE is assigned on more than one channel, a non-interlaced structurecan be used for channels other than the first interlaced channel.

In a second example, the interlace may be defined with respect to thesystem bandwidth and not a particular channel such as the 80 MHz systemBW which included 4 channels (20/40/60/80 MHz) of 20 MHz BW each asdiscussed earlier. See FIG. 12C where interlace 2 has PRBs that areequally spaced 10 PRBs apart across four 20 MHz channels. For example,the UE may be assigned a cluster of interlaces or cluster of partialinterlaces with equally spaced PRBs across the entire system bandwidthand not just one channel. Note if an interlace consists of PRB 0, 10,20, . . . , 390, etc., a partial interlace may not need to use all ofthe RBs in an interlace. Here, the interlace may have 400 PRBs with 10PRB spacing resulting in 40 PRBs equally spaced) A partial interfacecould be assigned to a UE with PRB 0, 10, 20, . . . , 150 (i.e., a total16 PRBs with 10 PRB equal spacing) as an example. Thus, the UE can beassigned with multiple continuous clusters of one or more interlaces orpartial interlaces which can span more than one channel.

FIG. 13 illustrates certain components that may be included within abase station 1301. The base station 1301 may be an access point, aNodeB, an evolved NodeB, etc. The base station 1301 includes a processor1303. The processor 1303 may be a general purpose single- or multi-chipmicroprocessor (e.g., an ARM), a special purpose microprocessor (e.g., adigital signal processor (DSP)), a microcontroller, a programmable gatearray, etc. The processor 1303 may be referred to as a centralprocessing unit (CPU). Although just a single processor 1303 is shown inthe base station 1301 of FIG. 13 , in an alternative configuration, acombination of processors (e.g., an ARM and DSP) could be used.

The base station 1301 also includes memory 1305. The memory 1305 may beany electronic component capable of storing electronic information. Thememory 1305 may be embodied as random access memory (RAM), read onlymemory (ROM), magnetic disk storage media, optical storage media, flashmemory devices in RAM, on-board memory included with the processor,EPROM memory, EEPROM memory, registers, and so forth, includingcombinations thereof.

Data 1307 and instructions 1309 may be stored in the memory 1305. Theinstructions 1309 may be executable by the processor 1303 to implementthe methods disclosed herein. Executing the instructions 1309 mayinvolve the use of the data 1207 that is stored in the memory 1305. Whenthe processor 1303 executes the instructions 1309, various portions ofthe instructions 1309 a may be loaded onto the processor 1303, andvarious pieces of data 1307 a may be loaded onto the processor 1303.

The base station 1301 may also include a transmitter 1311 and a receiver1313 to allow transmission and reception of signals to and from thewireless device 1301. The transmitter 1311 and receiver 1313 may becollectively referred to as a transceiver 1315. Multiple antennas 1317a-b may be electrically coupled to the transceiver 1315. The basestation 1301 may also include (not shown) multiple transmitters,multiple receivers and/or multiple transceivers.

The various components of the base station 1301 may be coupled togetherby one or more buses, which may include a power bus, a control signalbus, a status signal bus, a data bus, etc. For the sake of clarity, thevarious buses are illustrated in FIG. 13 as a bus system 1319. Thefunctions described herein in the flowchart of FIG. 10 , may beimplemented in hardware, software executed by a processor like theprocessor 1303 described in FIG. 13 .

FIG. 14 illustrates certain components that may be included within awireless communication device 1401. The wireless communication device1401 may be an access terminal, a mobile station, a user equipment (UE),etc. The wireless communication device 1401 includes a processor 1303.The processor 1403 may be a general purpose single- or multi-chipmicroprocessor (e.g., an ARM), a special purpose microprocessor (e.g., adigital signal processor (DSP)), a microcontroller, a programmable gatearray, etc. The processor 1403 may be referred to as a centralprocessing unit (CPU). Although just a single processor 1403 is shown inthe wireless communication device 1401 of FIG. 14 , in an alternativeconfiguration, a combination of processors (e.g., an ARM and DSP) couldbe used.

The wireless communication device 1401 also includes memory 1405. Thememory 1405 may be any electronic component capable of storingelectronic information. The memory 1405 may be embodied as random accessmemory (RAM), read only memory (ROM), magnetic disk storage media,optical storage media, flash memory devices in RAM, on-board memoryincluded with the processor, EPROM memory, EEPROM memory, registers, andso forth, including combinations thereof.

Data 1407 and instructions 1409 may be stored in the memory 1405. Theinstructions 1309 may be executable by the processor 1403 to implementthe methods disclosed herein. Executing the instructions 1409 mayinvolve the use of the data 1407 that is stored in the memory 1405. Whenthe processor 1403 executes the instructions 1409, various portions ofthe instructions 1409 a may be loaded onto the processor 1403, andvarious pieces of data 1407 a may be loaded onto the processor 1403.

The wireless communication device 1401 may also include a transmitter1411 and a receiver 1413 to allow transmission and reception of signalsto and from the wireless communication device 1401. The transmitter 1411and receiver 1413 may be collectively referred to as a transceiver 1415.Multiple antennas 1417 a-b may be electrically coupled to thetransceiver 1415. The wireless communication device 1401 may alsoinclude (not shown) multiple transmitters, multiple receivers and/ormultiple transceivers.

The various components of the wireless communication device 1401 may becoupled together by one or more buses, which may include a power bus, acontrol signal bus, a status signal bus, a data bus, etc. For the sakeof clarity, the various buses are illustrated in FIG. 14 as a bus system1419. It should be noted that these methods describe possibleimplementation, and that the operations and the steps may be rearrangedor otherwise modified such that other implementations are possible. Insome examples, aspects from two or more of the methods may be combined.For example, aspects of each of the methods may include steps or aspectsof the other methods, or other steps or techniques described herein.Thus, aspects of the disclosure may provide for receiving on transmitand transmitting on receive. The functions described herein in theflowchart of FIGS. 1A and 1B may be implemented in hardware, softwareexecuted by a processor like the processor 1403 described in FIG. 14 .

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notto be limited to the examples and designs described herein but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physical(PHY) locations. Also, as used herein, including in the claims, “or” asused in a list of items (for example, a list of items prefaced by aphrase such as “at least one of” or “one or more”) indicates aninclusive list such that, for example, a list of at least one of A, B,or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media caninclude RAM, ROM, electrically erasable programmable read only memory(EEPROM), compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that can be used to carry or store desired programcode means in the form of instructions or data structures and that canbe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include CD, laser disc, optical disc, digital versatile disc (DVD),floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

Techniques described herein may be used for various wirelesscommunications systems such as CDMA, TDMA, FDMA, OFDMA, single carrierfrequency division multiple access (SC-FDMA), and other systems. Theterms “system” and “network” are often used interchangeably. A CDMAsystem may implement a radio technology such as CDMA2000, UniversalTerrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95,and IS-856 standards. IS-2000 Releases 0 and A are commonly referred toas CDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to asCDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. A TDMA system mayimplement a radio technology such as (Global System for Mobilecommunications (GSM)). An OFDMA system may implement a radio technologysuch as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11(wireless fidelity (Wi-Fi)), IEEE 802.16 (WiMAX), IEEE 802.20,Flash-OFDM, etc. UTRA and E-UTRA are part of Universal MobileTelecommunications system (Universal Mobile Telecommunications System(UMTS)). 3GPP LTE and LTE-advanced (LTE-A) are new releases of UMTS thatuse E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-a, and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). CDMA2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the systems and radiotechnologies mentioned above as well as other systems and radiotechnologies. The description herein, however, describes an LTE systemfor purposes of example, and LTE terminology is used in much of thedescription above, although the techniques are applicable beyond LTEapplications.

In LTE/LTE-A networks, including networks described herein, the termevolved node B (eNB) may be generally used to describe the basestations. The wireless communications system or systems described hereinmay include a heterogeneous LTE/LTE-A network in which different typesof eNBs provide coverage for various geographical regions. For example,each eNB or base station may provide communication coverage for a macrocell, a small cell, or other types of cell. The term “cell” is a 3GPPterm that can be used to describe a base station, a carrier or componentcarrier (CC) associated with a base station, or a coverage area (e.g.,sector, etc.) of a carrier or base station, depending on context.

Base stations may include or may be referred to by those skilled in theart as a base transceiver station, a radio base station, an access point(AP), a radio transceiver, a NodeB, eNodeB (eNB), Home NodeB, a HomeeNodeB, or some other suitable terminology. The geographic coverage areafor a base station may be divided into sectors making up a portion ofthe coverage area. The wireless communications system or systemsdescribed herein may include base stations of different types (e.g.,macro or small cell base stations). The UEs described herein may be ableto communicate with various types of base stations and network equipmentincluding macro eNBs, small cell eNBs, relay base stations, and thelike. There may be overlapping geographic coverage areas for differenttechnologies. In some cases, different coverage areas may be associatedwith different communication technologies. In some cases, the coveragearea for one communication technology may overlap with the coverage areaassociated with another technology. Different technologies may beassociated with the same base station, or with different base stations.

The wireless communications system or systems described herein maysupport synchronous or asynchronous operation. For synchronousoperation, the base stations may have similar frame timing, andtransmissions from different base stations may be approximately alignedin time. For asynchronous operation, the base stations may havedifferent frame timing, and transmissions from different base stationsmay not be aligned in time. The techniques described herein may be usedfor either synchronous or asynchronous operations.

The DL transmissions described herein may also be called forward linktransmissions while the UL transmissions may also be called reverse linktransmissions. Each communication link described herein including, forexample, wireless communications system 100 of FIG. 1 may include one ormore carriers, where each carrier may be a signal made up of multiplesub-carriers (e.g., waveform signals of different frequencies). Eachmodulated signal may be sent on a different sub-carrier and may carrycontrol information (e.g., reference signals, control channels, etc.),overhead information, user data, etc. The communication links describedherein may transmit bidirectional communications using frequencydivision duplex (FDD) (e.g., using paired spectrum resources) or timedivision duplex (TDD) operation (e.g., using unpaired spectrumresources). Frame structures may be defined for FDD (e.g., framestructure type 1) and TDD (e.g., frame structure type 2).

Thus, aspects of the disclosure may provide for receiving on transmitand transmitting on receive. It should be noted that these methodsdescribe possible implementations, and that the operations and the stepsmay be rearranged or otherwise modified such that other implementationsare possible. In some examples, aspects from two or more of the methodsmay be combined.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), an ASIC, afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration). Thus, the functions described herein may be performed byone or more other processing units (or cores), on at least oneintegrated circuit (IC). In various examples, different types of ICs maybe used (e.g., Structured/Platform ASICs, an FPGA, or anothersemi-custom IC), which may be programmed in any manner known in the art.The functions of each unit may also be implemented, in whole or in part,with instructions embodied in a memory, formatted to be executed by oneor more general or application-specific processors.

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

What is claimed is:
 1. A method of wireless communication performed by auser equipment (UE), the method comprising: receiving access to at leastone interlace or at least one partial interlace of equally spacedphysical resource blocks (PRBs) across a plurality of channels within asystem bandwidth, the at least one interlace or the at least one partialinterlace defined based on an entirety of the system bandwidth, whereinthe at least one interlace or the at least one partial interlaceincludes multiple continuous PRB clusters spanning the plurality ofchannels; reducing resource allocation (RA) overhead by: receiving astarting PRB, resource block group (RBG), or interlace; spanning anumber of the RBs, RBGs, or interlaces across multiple channelsincluding unoccupied channels and guard bands; and automaticallyskipping PRBs, RBGs, or interlaces in the guard bands and in theunoccupied channels; and communicating via the at least one interlace orthe at least one partial interlace.
 2. The method of claim 1, wherein aRBG size corresponding to the at least one interlace or the at least onepartial interlace is based on a medium occupancy of the system bandwidthallocated to the UE, and wherein reducing the RA overhead furtherincludes: jointly coding a RA indication and a medium occupancy index,receiving the starting PRB in a first allocated channel and an end PRBin a last allocated channel; and receiving the medium occupancyindicating the first allocated channel and the last allocated channel,and wherein: the RBG size dynamically changes in response to changes inthe medium occupancy, and the medium occupancy corresponds to one ormore channels of the plurality of channels through which data istransmitted or received.
 3. The method of claim 1, further comprising:receiving, from a gNB, information comprising a medium occupancy and aRBG size, wherein the RBG size is based on the medium occupancy.
 4. Themethod of claim 3, wherein receiving the information includes receiving,on an L1 channel, a common signal that includes the information, andwherein there is an implicit mapping between the RBG size and the mediumoccupancy.
 5. The method of claim 1, further comprising, in response toan increase in a medium occupancy, receiving assignment of a coarser RBGsize for the RBG size.
 6. The method of claim 1, further comprising, inresponse to a decrease in a medium occupancy, receiving assignment of afiner RBG size for the RBG size.
 7. An apparatus for wirelesscommunication, the apparatus comprising: means for receiving access toat least one interlace or at least one partial interlace of equallyspaced physical resource blocks (PRBs) across a plurality of channelswithin a system bandwidth, the at least one interlace or the at leastone partial interlace defined based on an entirety of the systembandwidth, wherein the at least one interlace or the at least onepartial interlace includes multiple continuous PRB clusters spanning theplurality of channels; means for reducing resource allocation (RA)overhead, the means for reducing RA overhead including: means forreceiving a starting PRB, resource block group (RBG), or interlace;means for spanning a number of the RBs, RBGs, or interlaces acrossmultiple channels including unoccupied channels and guard bands; andmeans for automatically skipping PRBs, RBGs, or interlaces in the guardbands and in the unoccupied channels; and means for communicating viathe at least one interlace or the at least one partial interlace.
 8. Theapparatus of claim 7, wherein that at least one interlace comprises 400PRBs having 10 PRB spacing across four channels.
 9. The apparatus ofclaim 7, further comprising means for receiving information thatindicates a medium occupancy and a RBG size, and wherein the RBG size isbased on the medium occupancy.
 10. The apparatus of claim 9, furthercomprising means for receiving an additional guard band around anoccupied medium corresponding to the medium occupancy.
 11. The apparatusof claim 10, wherein the additional guard band is assigned around theoccupied medium to avoid adjacent channel leakage-power if the occupiedmedium is not fully occupied.
 12. The apparatus of claim 9, wherein theinformation that indicates the medium occupancy and the RBG size isincluded in a radio resource control (RRC) layer or is predefined. 13.The apparatus of claim 9, wherein the means for receiving theinformation includes means for receiving, on an L1 channel, a commonsignal that includes the information, and wherein there is an implicitmapping between the RBG size and the medium occupancy.
 14. The apparatusof claim 13, wherein the common signal is received in a first slot of atransmit opportunity (TXOP) and repeated in subsequent slots of theTXOP.
 15. The apparatus of claim 9, wherein the information includes abitmap and is received on a channel allocated to the apparatus, whereinat least one bit in the bitmap represents one or more RBGs, and whereinthere is an implicit mapping between the RBG size and a configuredbandwidth part (BWP).
 16. A user equipment (UE) comprising: a memory;and a processor coupled to the memory, the processor configured to:receive access to at least one interlace or at least one partialinterlace of equally spaced physical resource blocks (PRBs) across aplurality of channels within a system bandwidth, the at least oneinterlace or the at least one partial interlace defined based on anentirety of the system bandwidth, wherein the at least one interlace orthe at least one partial interlace includes multiple continuous PRBclusters spanning the plurality of channels; reduce resource allocation(RA) overhead, wherein, to reduce the RA overhead, the processor isconfigured to: receive a starting PRB, resource block group (RBG), orinterlace; span a number of the RBs, RBGs, or interlaces across multiplechannels including unoccupied channels and guard bands; andautomatically skip PRBs, RBGs, or interlaces in the guard bands and inthe unoccupied channels; and initiate communication via the at least oneinterlace or the at least one partial interlace.
 17. The UE of claim 16,wherein that at least one interlace comprises 400 PRBs having 10 PRBspacing across four channels.
 18. The UE of claim 16, wherein , toreduce the RA overhead, the processor is further configured to: jointlycode a RA indication and a medium occupancy index receive the startingPRB in a first allocated channel and an end PRB in a last allocatedchannel; and receive a medium occupancy indicating the first allocatedchannel and the last allocated channel.
 19. The UE of claim 16, whereinthe processor is further configured to receive information thatindicates a medium occupancy and a RBG size, and wherein the RBG size isbased on the medium occupancy.
 20. The UE of claim 19, wherein, toreceive the information, the processor is configured to receive, on anL1 channel a common signal that include the information, and whereinthere is an implicit mapping between the RBG size and the mediumoccupancy.
 21. A non-transitory processor-readable storage mediumstoring instructions that, when executed by a processor of a userequipment (UE), cause the processor to perform operations comprising:receiving access to at least one interlace or at least one partialinterlace of equally spaced physical resource blocks (PRBs) across aplurality of channels within a system bandwidth, the at least oneinterlace or the at least one partial interlace defined based on anentirety of the system bandwidth, wherein the at least one interlace orthe at least one partial interlace includes multiple continuous PRBclusters spanning the plurality of channels; reducing resourceallocation (RA) overhead by: receiving a starting PRB, resource blockgroup (RBG), or interlace; spanning a number of the RBs, RBGs, orinterlaces across multiple channels including unoccupied channels andguard bands; and automatically skipping PRBs, RBGs, or interlaces in theguard bands and in the unoccupied channels; and initiating communicationvia the at least one interlace or the at least one partial interlace.22. The non-transitory processor-readable storage medium of claim 21,wherein the operations further comprise receiving information thatindicates a medium occupancy and a RBG size, and wherein the RBG size isbased on the medium occupancy.
 23. The non-transitory processor-readablestorage medium of claim 22, wherein the operations further comprisereceiving an additional guard band around an occupied mediumcorresponding to the medium occupancy.
 24. The non-transitoryprocessor-readable storage medium of claim 23, wherein the additionalguard band is assigned around the occupied medium to avoid adjacentchannel leakage-power if the occupied medium is not fully occupied. 25.The non-transitory processor-readable storage medium of claim 22,wherein the information is included in a radio resource control (RRC)layer or is predefined.
 26. The non-transitory processor-readablestorage medium of claim 22, wherein the operations further includereceiving, on an L1 channel, a common signal that includes theinformation, and wherein there is an implicit mapping between the RBGsize and the medium occupancy.
 27. The non-transitory processor-readablestorage medium of claim 26, wherein the information is received in afirst slot of a transmit opportunity (TXOP) and repeated in subsequentslots of the TXOP.
 28. The non-transitory processor-readable storagemedium of claim 22, wherein the information includes a bitmap receivedon a UE specific channel, wherein at least one bit in the bitmaprepresents one or more RBGs, and wherein there is an implicit mappingbetween the RBG size and a configured bandwidth part (BWP).